Sewer pipe joint



June 4, 1946. E. M. DAVIDS 2,401,554

I SEWER PIPE JOINT Filed June 26, 1943 "Mann A .I 1 v w.

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M $W 1 ////|M to Gladding, McBean & $0., a corporation of Ealiiornia lies Angelica, habit, I

Application June 28. 1943, Serial No. 492,367

This invention relates to a pipe joint'end is particularly designed-for use in efiecting joints between adjacent sections of sewer pipe.

The conventional sewer pipe is formed of a ceramic material wherein the sections of pipe have at one end a spigot and at the other end a bell adapted to receive the spigot of the adjoining section. In the commercial production of sewer pipe the sections are not always uniformly made. Variations will occur depending upon the location of the pipe in the kiln at the time of firing and other irregularities will be present for numerous other reasons. It is desirable, however, to efiect a tight joint between the bell and spigot which would efiectively prevent penetration by roots. It is also desirable to effect such joint in such a. manner that some flembility is present to take care of the settling of the sewer pipe after it has been installed. Heretoiore rubber sealing elements or gaskets have been employed which substantially fill the space between the exterior of the spigot and the interior of the bell. These rubber sealing elements while they produce a reasonably tight joint and permit of some fienibility and also allow for the irregularities in the pipe occasioned by its construction'are relatively expensive due to the volume of rubber required.

2 Claims. (cl. es -n5) 2 pipe that is intended to receive the spigot end it. In carrying out my invention I preferably roughen or groove the exterior of the spigot as at it? to facilitate the anchoring thereto of a surrounding layer of self-hardening composition it which may be any conventional self-hardening joint compound, such as sulphur and silica.

It is not necessary to groove the spigot ii in m all instances as sometimes the exterior of the pipe as naturally formed iin conventional practice, is sufficiently rough to adequately anchor or fasten the surrounding. layer of material it thereto.

The bushing is is applied by inserting the spigotin a machined cylindrical steel mold and filling the mold ,with the compound or self-hardening material it which, when it hardens, i'orms a a surrounding bushing on the cylindrical end of the Eli ' A primary object 0! the present invention is to provide ail-improved joint which will allow for the irregularities in the pine occasioned by 30 its construction which will be tight and resist the penetration of roots, and which at the same time requires only a very small iractiomof the amount of rubber that has heretofore been used in the sealing elements; o l

Another object of the invention resides in the method of constructing the joint to accomplish the abovesmentioned desiderata.

With the foregoing and other objects in view,

which will be made manifest in the following detailed description and specifically pointed out in the appended claims, reference is had to the ac companying drawing for an illustrative embodiment of the invention, wherein; I 1

Figure l is alongitudinal section through one form or pipe joint embodying my invention; and

Fig. 21s a longitudinal section through alternative form of pipe joint embodying my invention.

er'ring to the accompanying drawing wherein similar reference characters designate siml-= lar parts throughout, ill designates the spigot end of a section of c'onventionalsewer pipe whichis usually formed of a ceramic material; ii incitspigotthe exterior surface of which is accurately and cylindrically formed. Thus, even though the spigot end it may be highly irregular in shape due to firing or otherwise, by molding or casting the layer it thereabout these inequalities are effectively taken up.

The mold-preferably provides a slight shoulder it adjacent the end of the surrounding hushing it against which can be positioned a small narrow rubber band it.

in the form shown in Fig. ,l, the interior of.

the hell it is similarly grooved or roughened as indicated at it, and a substantially cylindrical l steel core is positioned in the bell so as to cooper- .ate with its interior surface to form a mold. within which joint compounding or other 'self hardening composition may be molded indicated at ll. it will benoted that there is a clearance it-between the exterior of the band it on the spigot ill and the interior of the lining ii on the interior of the bell. This clearance permits of a limited amount of disalignment of the adjoining sections of sewer pipe which may be cccasioned by the settling of the pipe.

The interior surface oi the lining ii is not per- .fectly cylindrical but preferably has a slight taper. In assembling the adjoining sections of sewer pipe constructed as above described, the spigot end with its attached bushing id and applied rubber band it is forced into the hell it with its lining ill Due to the slight taper the rubber band is highly compressed about the bushing it and .under compression the rubber becomes very hard and stiff so that it will not on1y,serve effectively as a gasket to prevent leakage but will efiectively tee the-bell end of an adjoining secticnoi sewer E prevent roots penetrating the joint.

It will thus be appreciated that the improved sections which may be irregular and non-uniform. The spigot and bell ends of the sections are rendered uniform by molding thereon the bushing I 3 and the lining l1. Instead of filling the space between the spigot ill and the interior of the bell with a rubber sealing element utilizing 'by means of the clearance is without loosening the joint or rendering it subject to penetration by roots.

In the form illustrated in Fig. 2, the bell 2| is preferably internally grooved as at 22 and lined with self-hardening material 23, the interior of which has a slight taper. In this form of construction, instead of molding or casting a bushing it around the spigot end 20 of the adjoining sec-- tion of pipe the spigot end 2t isrecessed and joint enables the use of commercial sewer pipe j shouldered as at 2 3 adjacent its end toaccornmo 7 date the rubber band 25.

This type ofconstruction may be advantageously employed where the spigot ends of the sewer pipe can be constructed in a substantially uniform manner. Usually the recessed end and shoulder 23 are formed on the sewer pipe as it is originally molded. In assembling this joint the spigot end is merely thrust into the lining 23 in the bell with the result that due to the slight Y taper on the interior of the lining the small rubber band is highly compressed and rendered very stiff andhard because of the compression. In this form also the clearance space 28 between the exterior of the spigot and the interior 4. of the lining accommodates disaligning oi the adjoining sections.

From the above-described construction it will be appreciated that a new sewer pipe joint and method of making the same have been developed which enables the use oi commercially produced sewer pipe which may have inequalities or irregularities. It consists of rendering either one or both ends of the sewer pipe sections uniform by applying thereto a surface layer of self-hardening material, provision being made for fitting on the spigot end of the pipe a small narrow rubber bandwhich on being inserted into the slightly tapered lining on the bell will be highly compressed.

Various changes may be made in the details of construction without departing from the spirit or scope of the invention as defined by the appended claims.

I claim:

l. A sewer pipe joint having a bell and spigot, the bell having a lining molded therein presenting on its. interior a smooth, uniform surface of revolution, the spigot having on its exterior a shoulder adjacent one end, and a rubber band positioned on the spigot against the shoulder and extending therefrom to the end of the spigot adapted to be carried thereby into the lining on the bell in assembling the joint.

2. A sewer pipe joint having a bell and spigot, the bell being lined with'a. molded material and presenting on its interior a smooth, uniform sur-- face of revolution, the spigot having a molded bushing on its exterior presenting a smooth, uniform external surface of revolution, said bushing presenting a, shoulder adjacent one end, a rubber band positioned against said shoulder and adapted to be carried thereby into the lining into the bell on assembling the joint.

ERNEST K DAVmS.

or permits of slight 

